Author

Year of Publication

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Health Sciences

Department

Rehabilitation Sciences

First Advisor

Dr. Carl G. Mattacola

Second Advisor

Dr. Anne D. Olson

Abstract

Articular cartilage defects in the knee are common, and can result in pain, decreased function and decreased quality of life. Untreated defects are considered to be a risk factor for developing osteoarthritis, a progressive degenerative joint disease with minimal treatment options. To address these issues, various surgical procedures are available to treat articular cartilage defects in the knee. While these procedures overall have positive results, after surgery patients experience large and persistent deficits in quadriceps strength. A contributing factor to this post-surgical weakness is believed to be the extended post-operative non-weight bearing period, with full weight bearing not initiated until approximately 4 – 6 weeks after surgery. During this non-weight bearing period a minimal amount of demand is placed upon the muscle. Subsequently, the quadriceps muscle undergoes a large degree of atrophy with a significant decrease in muscle strength. Muscular strength deficits reduce the knee joint stability, also increasing the risk of osteoarthritis development. Interventions that can be used to facilitate quadriceps strength while protecting the articular cartilage repair are needed. Neuromuscular electrical stimulation (NMES) is an effective post-knee surgery rehabilitation technique to regain quadriceps musculature. In recent years manufactures have been developing knee sleeve garments integrated with NMES allowing for portability of the NMES treatment.

The primary aim of this study was to evaluate the effectiveness of a 12-week home-based neuromuscular electrical stimulation treatment on post-surgical clinical outcomes (quadriceps strength, lower extremity function, and patient reported outcomes) after articular cartilage knee surgery. Patients were randomized between a standard of care home-treatment group and a NMES home-treatment group. Patients completed isometric quadriceps strength testing, the Y-balance test, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) before surgery and at 3-months after surgery. The secondary aims of this study were to determine the most effective NMES parameters for post-surgical quadriceps strength; and to develop a framework to identify factors that may influence a patient’s adherence to a prescribed therapy program.

From our results we can make several conclusions. First, we found only a small number of studies utilize similar parameters for post-surgical quadriceps strength treatments. The majority of the parameters reported in the literature were highly variable between studies. Second, clinicians can utilize the expanded Health Belief Model to identify situational and personal factors unique to a patient that may impact adherence to a prescribed treatment. Clinicians can then implement the proposed interventional strategies to address the identified situational and personal factors. Finally, there was no difference in quadriceps strength, lower extremity function, or self-reported scores at 3-month between a home-based NMES treatment and a standard of care home-based treatment. Patients’ adherence to the treatment protocols may have been a major factor contributing to these results. Utilizing a model, such as the proposed expanded Health Belief Model, may assist clinicians in improving a patients’ adherence to future prescribed home-treatment programs.